ABC News(NEW YORK) -- Sen. Lindsey Graham, (R-S.C.), said Sunday he does not believe that U.S. Ambassador to the United Nations Susan Rice relied on the most accurate information from the intelligence community when she provided a public explanation for the attack on the U.S. consulate in Benghazi, Libya.

“I’m increasingly convinced that the best and current intelligence assessment on 16 September went against the video. The video was a political smokescreen,” Graham said on “This Week With George Stephanopoulos.” “The actual facts were this was a coordinated, pre-planned terrorist attack.”

Speaking at the United Nations on Wednesday, Rice said that some of the attacks leveled against her by Republican lawmakers were “unfounded.”

“When discussing the attacks against our facilities in Benghazi, I relied solely and squarely on the information provided to me by the intelligence community. I made clear that the information was preliminary and that our investigations would give us the definitive answers,” Rice said.

Graham rejected that explanation again Sunday.

“My belief is that there was a mountain of intel to dispute the video characterization,” Graham said Sunday. “There was really no intel saying this was a spontaneous event.”

Asked whether he would oppose Rice’s potential nomination as Secretary of State, Graham would not repeat his past assertions that she should be disqualified for the post if President Obama chooses to nominate her.

“When she comes over, if she does, there will be a lot of questions asked of her about this event and others,” Graham said. “But I do not believe the video is the cause … I don’t believe it was ever the reason for this. That was a political story, not an intel story, and we’re going to hold people accountable.”

Earlier this month, Graham had said that because of the explanation Rice gave for the Benghazi attack, he was “dead set” on making sure Rice isn’t “promoted.”

On Sunday he added that he would pursue an investigation into Benghazi “like we got to the bottom of Iran-Contra,” referring to the 1980s scandal when the Reagan administration made a secret deal with Iran to sell them weapons in exchange for the release of American hostages held in Lebanon, and some of the money from the sale was diverted to support the Contra rebels fighting the Sandinista government in Nicaragua.

“We’re not going to let up on this,” he said.

Democratic Sen. Dick Durbin insisted that Republicans are unfairly focusing on Rice’s statements after the attack.

“If this were an NFL game, the critics of Ambassador Rice would be penalized for piling on,” Durbin said. “For goodness sake, she got the report from the intelligence community; she dutifully reported it to the public, just exactly what we expect her to do.

“They had decided not to include the al Qaeda references so we wouldn’t compromise our sources in Benghazi and in Libya,” he said.